Priority is claimed with respect to application Ser. No. 199 09 465.9 filed in Germany on Mar. 4, 1999, the disclosure of which is incorporated herein by reference.
The invention relates to a device for displacing rod-shaped objects used in the tobacco-processing industry, in particular cigarettes and/or filters which are located in receptacles of a revolving conveyor, in the direction of their longitudinal axes, the device having a least one revolving pressing ring, which is pressed against at least one frontal face of the objects in a displacement area.
Rod-shaped objects used in the tobacco-processing industry are understood to be cigarettes with and without filters, small cigars, cigars as well as filter rods.
It is sometimes necessary in the course of the production or further processing of the above mentioned rod-shaped objects to displace these objects in the longitudinal direction. It is therefore possible for an object, which is not in the desired position, to be pushed into the latter in the course of the conveyance. An example of this is provided by the preparation of groups of cigarettes and filter plugs for being enclosed by a small glued connecting paper. In the process, two axially aligned cigarettes are transferred into a receptacle of a revolving conveyor, for example a rotating drum. Then an axially aligned filter plug of twice the normally used length is placed between the two axially aligned cigarettes in the receptacle. In order to assure a trouble-free placement of the filter plug, spaces exist between the cigarettes and the filter plug of a group, which must be removed by the axial displacement of the cigarettes, so that the components consisting of cigarettes and filter plug of a group are brought together and touch each other. A suitable displacement mechanism is described in German Letters Patent 1 008 173, wherein so-called wobble rings are fastened by means of a plurality of springs on the hub of a drum which conveys the groups in troughs. Actuating elements at a displacement location push the rings in the direction toward the groups, wherein the rings displace the cigarettes located on the outside toward the filter plug located between them. Downstream of the displacement location the springs push the rings back again, so that fresh groups of objects can be received in the troughs after the pushed-together groups have been transported away. This type of a resilient suspension of the displacement ring via a number of springs is mechanically delicate and is not trouble-free, particularly at high speeds, because of the springs alone, which tend to break often.
An object of the invention is to provide a mechanically sturdy displacement device which eliminates trouble caused by spring breakage of the existing device and is suitable for high speeds.
The above and other objects are accomplished according to the invention by the provision of a device for displacing rod-shaped objects used in the tobacco-processing industry, in particular cigarettes and/or filters, in a direction of the longitudinal axes of the rod-shaped objects, comprising: a revolving conveyor having receptacles each for receiving a plurality of the rod-shaped objects in an axially aligned formation, the rod-shaped objects presenting at least one exposed frontal face; at least one revolving pressing ring arranged for pressing against the at least one frontal face of the objects in a displacement area, the pressing ring comprised at least partially of a spring-elastic material selected from a group consisting of a silicon material, rubber-elastic plastic material and a metallic material.
A particularly advantageous further development of the invention consists in an embodiment of the conveyor as a revolving, i.e. rotating, drum, which is provided with troughs in which the objects are conveyed, so that they can be displaced in the direction of their longitudinal axes. In this case the pressing ring then preferably revolves synchronously with the drum. In a further development of the invention, the pressing ring is fastened in a preferably inner circular end area on a hub of the drum. This results in a mechanically very sturdy displacement device contrasted to known devices.
An important further development of the device in accordance with the invention is distinguished in that the pressing ring has a concave shape on the side facing away from the drum, i.e. that it has a concave recess. With such a design of the pressing ring the latter can be deformed easily and with little wear by the actuating element. A further advantageous embodiment of the invention resides in the fastening of an outer ring consisting of a rigid material, for example metal, on the outer end area of the pressing ring made of silicon. The rigid outer ring can advantageously have an opening in the area of the front face of an object.
In the above mentioned special use of the invention, namely in connection with a displacement drum for cigarette-filter groups, pressing rings with actuating elements are advantageously provided on both sides of the revolving conveyor.
Besides the preferred silicon material for the pressing rings, the invention also relates to pressing rings made of a similar suitable spring-elastic material, for example a rubber-elastic plastic material, or a corresponding metallic material.
The particular advantage of the invention lies in that the pressing ring itself can be resiliently designed, but still be of sufficient sturdiness, so that it operates with sufficient dependability even at high speeds. The use of silicon has the additional advantage that it is quite harmless in view of food safety regulations, even if small particles should get into the objects.